from manim import *



class math1(MovingCameraScene):
    def construct(self):
        self.camera.background_color = BLACK  # 设置背景颜色
        self.camera.frame_width = 100  # 设置边框宽度
        self.camera.frame_height = 60  # 设置边框高度
        self.camera.pixel_height = 1080  # 设置像素高度
        self.camera.pixel_width = 1920  # 设置像素宽度
        self.camera.center = ORIGIN  # 设置中心点位置
        self.camera.scale_factor = 1.0  # 设置缩放因子
        #设置横线
        for i in range(6*2+1):       
            dot1=Dot([-50,5*(i-6),0]).set_opacity(0.5)
            dot2=Dot([50,5*(i-6),0]).set_opacity(0.5)
            if i==6:
                line1=Line(dot1,dot2).set_color(WHITE).set_opacity(0.5)
                
            else:
                line1=Line(dot1,dot2).set_color(WHITE).set_opacity(0.5)
               
            self.add(dot1,dot2,line1)
        #设置竖线
        for i in range(10*2+1):        
            dot3=Dot([(i-10)*5,-30,0]).set_opacity(0.5)
            dot4=Dot([(i-10)*5,30,0]).set_opacity(0.5)
            if i==10:
                line2=Line(dot3,dot4).set_color(WHITE).set_opacity(0.5)
                
            else:
                line2=Line(dot3,dot4).set_color(WHITE).set_opacity(0.5)
            self.add(dot3,dot4,line2)
        #设置三个点
        dot1 = Dot(radius=1, color=RED)  
        dot1.move_to([-47.5,27.5,0]) 
        dot2 = Dot(radius=1, color=YELLOW)  
        dot2.move_to([-42.5,27.5,0])  
        dot3 = Dot(radius=1, color=GREEN)  
        dot3.move_to([-37.5,27.5,0])
        #镜头跟进效果 
        self.camera.frame.save_state()
        #题目出现
        text = Tex(r"\text{已知}$f\left( x\right) $\text{连续,}$f\left( x^{2}+1\right) -f\left( x^{2}\right) =x( x > 0) ,$"
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0)
        text1 = Tex(
                   r"$\int _{0}^{1}f\left( x\right) dx=1$\text{,则}$\int ^{2}_{1}f\left( x\right) dx=$"
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([-7,-5,0])

        self.play(Write(text),self.camera.frame.animate.scale(0.8))
        self.play(Write(text1))
        self.wait()
        #镜头拉回
          #分析文本
        text100=MarkupText("<b><i>分析/解：</i></b>",color=PINK).scale(5.0).move_to([-38,12.5,0])
        self.play(Restore(self.camera.frame))
        self.play(Create(text100),FadeIn(dot1),run_time=0.1)
        self.play(FadeIn(dot2),run_time=0.1)
        self.play(FadeIn(dot3),run_time=0.1)
        #题目向上移动
        self.play(text.animate().move_to([0,20,0]),text1.animate().move_to([-7,15,0])) 

        #待求积分
        text2 = Tex(
                   r"\text{待求积分}",color=LOGO_GREEN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([-25,5,0])
        #框框闪动
        rectangle=Rectangle(color=BLUE,fill_opacity=0.0,width=17,height=5
                            ,stroke_color=RED,stroke_width=20)
        rectangle.move_to([2.5, 15, 0])
        self.play(Create(rectangle),Create(text2))
        self.play(FadeOut(rectangle))

        #箭头+文本
        text4 = Tex(
                   r"\text{转化}",color=BLUE
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([-10,8,0])
        arrow = Arrow(start=[-18,5,0],end=[0,5,0],color=RED
                       , stroke_width=20, tip_length=1)

        self.play(GrowArrow(arrow),Create(text4))


        #待求积分
        text3 = Tex(
                   r"\text{已知积分}",color=LOGO_GREEN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([8,5,0])
        #框框闪动
        rectangle1=Rectangle(color=BLUE,fill_opacity=0.0,width=17,height=5
                            ,stroke_color=RED,stroke_width=20)
        rectangle1.move_to([-16.5, 15, 0])
        self.play(Create(rectangle1),Create(text3))
        self.play(FadeOut(rectangle1))


        rectangle2=Rectangle(color=BLUE,fill_opacity=0.0,width=27,height=5
                            ,stroke_color=RED,stroke_width=20)
        rectangle2.move_to([4, 20, 0])
        self.play(Create(rectangle2))
        self.play(FadeOut(rectangle2))

        #箭头+文本

        text5 = Tex(
                   r"\text{令}$t=x-1$",color=BLUE
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([-33,-5,0])
        arrow1 = Arrow(start=[-25,3,0],end=[-20,-10,0],color=RED
                       , stroke_width=20, tip_length=1)

        self.play(GrowArrow(arrow1),Create(text5))

        #文本

        text6 = Tex(
                   r"$\int _{0}^{1}f\left( t+1\right) dt$",color=LIGHT_BROWN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).move_to([-10,-10,0])
        self.play(Create(text6))

        #半透明框框扩展

         #半透明矩阵扩展
        rectangle3=Rectangle(color=YELLOW,fill_opacity=0.3,width=1,height=2.8
                            ,stroke_color=YELLOW,stroke_width=0).move_to([4,20,0])
        self.play(
            rectangle3.animate.stretch(26,dim=0)
        )

        #文本
        text7 = Tex(
                   r"$f\left( x+1\right) -f\left( x\right) =\sqrt{x}$",color=GREEN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).next_to(rectangle3,UP,buff=1)
        self.play(Create(text7))

        text8 = Tex(
                   r"$=\int _{0}^{1}\left( f\left( t\right) +\sqrt{t}\right) dt$",color=GREEN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).next_to(text6,RIGHT,buff=1)
        self.play(Create(text8))

        #箭头

        arrow2 = Arrow(start=[7.5,-6,0],end=[9,3,0],color=RED
                       , stroke_width=20, tip_length=1)

        self.play(GrowArrow(arrow2))

        #文本

        text9 = Tex(
                   r"$=\dfrac{5}{3}$",color=GREEN
                   ,tex_template=TexTemplateLibrary.ctex).scale(5.0).next_to(text8,RIGHT,buff=1)
        self.play(Create(text9))

















        self.wait()
